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Subject: Re: [OMPI users] MPI_THREAD_FUNNELED and enable-mpi-thread-multiple
From: Brian Budge (brian.budge_at_[hidden])
Date: 2013-06-14 12:46:30


I'd like to bump this question. I also wanted to ask: I've been
searching the archives, and it seems that in past versions of OMPI,
only MPI_THREAD_SINGLE was available from the default configuration of
OMPI. It seems that as long as calls to MPI were serialized, however,
there were no issues. Is this still the case in 1.6 and 1.7 series?

Thanks,
  Brian

On Mon, Feb 4, 2013 at 9:09 PM, Roland Schulz <roland_at_[hidden]> wrote:
>
>
>
> On Mon, Jan 28, 2013 at 9:20 PM, Brian Budge <brian.budge_at_[hidden]> wrote:
>>
>> I believe that yes, you have to compile enable-mpi-thread-multiple to
>> get anything other than SINGLE.
>
>
> I just tested that compiling with enable-opal-multi-threads also makes
> MPI_Init_thread return MPI_THREAD_FUNNELED.
> Does enable-opal-multi-threads have any performance impact? According to
> http://www.open-mpi.org/community/lists/users/2012/10/20587.php
> enable-mpi-thread-multiple has significant performance impact (at least for
> IB). But I couldn't find any description of whether this is also true for
> enable-opal-multi-threads.
>
> Also why is enable-opal-multi-threads required for MPI_THREAD_FUNNELED? This
> was asked before (e.g.
> http://www.open-mpi.org/community/lists/devel/2010/05/7900.php) but I
> couldn't find any answer. What does the option change? The README states:
> "Enables thread lock support in the OPAL and ORTE layers.", but that is not
> very useful for a user. Also why is it not enabled by default?
>
> Roland
>
>>
>>
>> Brian
>>
>> On Tue, Jan 22, 2013 at 12:56 PM, Roland Schulz <roland_at_[hidden]> wrote:
>> > Hi,
>> >
>> > compiling 1.6.1 or 1.6.2 without enable-mpi-thread-multiple returns from
>> > MPI_Init_thread as provided level MPI_THREAD_SINGLE. Is
>> > enable-mpi-thread-multiple required even for
>> > MPI_THREAD_FUNNELED/MPI_THREAD_SERIALIZED?
>> >
>> > This question has been asked before:
>> > http://www.open-mpi.org/community/lists/users/2011/05/16451.php but I
>> > couldn't find an answer.
>> >
>> > Roland
>> >
>> > --
>> > ORNL/UT Center for Molecular Biophysics cmb.ornl.gov
>> > 865-241-1537, ORNL PO BOX 2008 MS6309
>> >
>> > _______________________________________________
>> > users mailing list
>> > users_at_[hidden]
>> > http://www.open-mpi.org/mailman/listinfo.cgi/users
>> _______________________________________________
>> users mailing list
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>>
>>
>>
>>
>
>
>
> --
> ORNL/UT Center for Molecular Biophysics cmb.ornl.gov
> 865-241-1537, ORNL PO BOX 2008 MS6309
>
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